1. Field of the Invention
The present invention relates to a moon grid for transmission electron microscopy tomography and preparation method thereof, and, more particularly, to a moon grid for transmission electron microscopy tomography, which comprises a mesh sheet for protecting an upper objects and a support film formed on the mesh sheet and having nanoparticles dispersed throughout and preparation method thereof.
2. Description of the Related Art
Transmission electron microscopy (TEM) is considered to be the most common tool for studying materials and biomedical materials on a nano scale.
Because the TEM is generally used to observe 2D images formed by electrons transmitted through a sample, the spatial resolution thereof is as sharp as about 0.1 nm.
However, information about the sample in the thickness direction causes problems in which the shadow of an object positioned on the electrons in a traveling direction overlaps underlying objects, or information of objects on top overlaps the information of underlying objects. In this case, it is difficult to correctly analyze overlapping information.
In order to solve or mitigate the above problems, recently, TEM tomography or STEM tomography is developed using a CT (Computed Tomograph) in the medical field, and further, the application range thereof is widened not only to the 3D structural analysis of amorphous materials, polymeric materials (chemical materials) and biomedical materials, but also to the short circuit analysis of semiconductors.
The procedure of obtaining a 3D image of a sample using TEM tomography or STEM tomography is briefly described below.
First, a thin film sample for TEM tomography is prepared. The preparation of the thin film sample may be conducted using any one process selected from among ultramicrotomy, dispersion, and FIB (Pick-up, micro-sampling). In the case where the biomedical or polymeric thin film sample is prepared through ultramicrotomy, dyeing may be performed.
The thin film sample is attached to a grid, and markers are also attached thereto.
The grid to which the thin film sample and markers are attached is placed in the TEM holder for TEM tomography or STEM tomography, and is then photographed, thus obtaining 2D images. As such, the respective 2D images are obtained by continuously tilting the thin film sample.
The 2D images are processed using a computer and are thus reconstructed into a 3D image.
As such, reconstruction of the 2D images into the 3D image is realized using the attached markers as reference points.
In this way, the markers play an important role in reconstructing the 2D images into the 3D image, and thus, depending on whether the size, number, and distribution of the attached markers are appropriate, the resolution of TEM tomography or STEM tomography, and even the success or failure of TEM tomography or STEM tomography, may be determined.
Further, a lot of time and effort are required to set conditions for the attachment of the markers depending on the type of thin film sample. In some cases, the markers fail to be attached. That is, attributable to reasons such as excessive attachment of the markers and so on, problems in which the thin film sample is hidden or attachment of the markers fails occur.
Because the above work greatly hinders efficient TEM tomography or STEM tomography and consumes unnecessary time, the procedure of attaching the markers needs to be improved in order to accomplish high efficiency.
Therefore, the present inventors, researching for solving the above disadvantages and problems encountered in the related art, have prepared a moon grid for TEM tomography, comprising a mesh sheet for protecting an upper structure and a support film formed on the mesh sheet and having nanoparticles dispersed throughout, and found that the moon grid for TEM tomography does not need for the additional attachment of markers in the course of preparation of a sample, thereby efficiently create a 3D image. Based on this finding, the present invention was completed.